| Analysis | Applications | Machineability_and_Weldability | Heat_Treating | Tolerances | Speedy Metals items |
AISI 8620 is an alloy carburizing steel when thermally treated develops a hard outer case with a soft ductile core. Carefully controlled proportions of chromium, nickel and molybdenum are responsible for the extensive use as a carburizing alloy steel, with valuable features including extreme surface hardenability and good internal strength. Has minimum distortion and growth characteristics. 8620 has good machinability and responds well to polishing.
8620 cold roll bars conforms to ASTM A331
8620 applications include gears, pinions, cams, cranks, clutch shafts, shafting, axles, tie bars, collets, bushings, heavy duty pins, bolting, springs, hand tools, die cases, and a multitude of machinery parts and components
8620 has a machinability rating at 66% of B1112. Average cutting speed 127 ft/min.
8620 can be forged at 2200° down to 1800° F prior to hardening or carburizing.
8620 is excellent for welding applications
8620 can be hardened to 1500° F followed by water quench. Carburize at 1650° - 1700° F in an appropriate carburizing medium and oil quench to harden. Tempering of carburized parts is done at 250° - 300° F and will result in the alloy having a core strength of approximately 135,000 psi minimum. Tempering of heat treated and water quenched parts (not carburized) is done at 400° - 1300° F, with greater hardness the lower the tempering temperature.
Rounds
| Up to 1-1/2" incl. | -.002 |
| Over 1-1/2 to under 2-1/2 | -.003 |
| Over 2-1/2 to 4" incl. | -.004 |